A good method of discovery is to imagine certain members of a system removed and then see how what is left would behave: for example, where would we be if iron were absent from the world: this is an old example.

To make a vow is a greater sin than to break one.

To write brashly about some things, it is almost necessary not to know much about them.

Reason now gazes above the realm of the dark but warm feelings as the Alpine peaks do above the clouds. They behold the sun more clearly and distinctly, but they are cold and unfruitful.

If it were true what in the end would be gained? Nothing but another truth. Is this such a mighty advantage? We have enough old truths still to digest, and even these we would be quite unable to endure if we did not sometimes flavor them with lies.

Everyone is a genius at least once a year.

If there were only turnips and potatoes in the world, someone would complain that plants grow the wrong way.